Modulation of Growth Media Influences Aggregation and Biofilm Formation between Azotobacter chroococcum and Trichoderma viride

The effect of growth media manipulation on the in vitro biofilm forming ability of Azotobacter chroococcum MTCC 25045 and Trichoderma viride ITCC 2211, both as individual cultures and co-culture was evaluated for 16 days. Growth curves (Bioscreen C lab system) and type of microbial population (planktonic and biofilm) helped to validate the aggregation and biofilm data. Modulation of combinations of routine growth media-Jensen's broth (J) and potato dextrose broth (P) by changing their ratios (100, 75: 25, 50: 50, and 25: 75) was undertaken. In individual bacterial or fungal inoculation, the growth media - J25: P75 and P100 caused significantly (p < 0.01) higher growth, aggregation, and biofilm formation. In co-culture, J25: P75 medium showed enhanced planktonic as well as biofilm population, aggregation, and biofilm formation followed by J50: P50 and J75: P25 media. This is a first report on interrelationships among growth, aggregation and biofilm formation in relation to medium optimization for fungal-bacterial biofilm development.